Associations between the size of hurricane rain fields at landfall and their surrounding environments

Abstract

This study examines relationships between the extent of hurricane rain fields, storm size, and the environment surrounding the storm. A Geographic Information System is employed to measure the extent of the rain fields in each quadrant of 31 hurricanes at landfall-time. After correlating the extents with measures of storm size, multiple linear regression models are developed to determine which atmospheric forcing(s) at 0, 12, and 24 h prior to landfall are most highly related to rain field size in each quadrant. Results show that the radius of the outermost closed isobar encompasses the rain fields in 90% of the observations. Strong vertical wind shear from the southwest correlates with a larger (smaller) rain field extent toward the northeast (southwest), while higher relative humidity values correlate with a larger extent toward the northwest, southwest, and southeast. Storm intensity and location also exhibit statistically significant correlations with rain field size.